Structure Exercise

Objective

To get practice writing C programs, including structs.

Task

For this lab, you will create a simple structure and a few functions to operate on it. The structure will represent a high score in a video game and will contain two fields:

The name of the player which can be three characters long (not including the NULL terminator).
The score which is an integer.

You should write three functions which work on these structures:

score_set - this takes a pointer to a score, a string and an integer. It should check that the string is three characters or less, and that the integer is non-negative. If either constraint is violated this function should return 0. If the data is OK, it should store those values in the score object passed in, and return 1.
score_print - this function should take a pointer to a score structure and print it to the screen. It should print the name, then a space, and then the score value.
score_compare - this function should take two pointers to structures. It should compare their score values. If the first one is less, it should return 1. If the second one is less, it should return -1. If they are equal, it should return 0.

Sample Run

You should test your structure and functions with the following main function:


#include <stdlib.h>

int main() {
    /* create an array of scores */
    Score scores[10];

    /* put in some test data */
    score_set(&scores[0], "IAN", 750);
    score_set(&scores[1], "BOB", 1200);
    score_set(&scores[2], "ADA", 3500);
    score_set(&scores[3], "SUE", 900);
    score_set(&scores[4], "EVA", 500);
    score_set(&scores[5], "BEN", 1500);
    score_set(&scores[6], "ROY", 3000);
    score_set(&scores[7], "KIM", 1250);
    score_set(&scores[8], "VIC", 2500);
    score_set(&scores[9], "DAN", 1800);

    /* sort them using the compare function above */
    qsort(scores, 10, sizeof(Score), 
        (int (*) (const void*, const void*)) &score_compare);

    /* display them */
    for (int i = 0; i < 10; i++) {
        score_print(&scores[i]);
    }

    return 0;
}

This program would output the following:

ADA 3500
ROY 3000
VIC 2500
DAN 1800
BEN 1500
KIM 1250
BOB 1200
SUE 900
IAN 750
EVA 500

Submitting

When you are done, please submit the C code under the assignment in Canvas.